电磁铁传热特性及散热优化的数值模拟

电磁铁是电液控制系统的核心液压元件，被广泛应用于航空航天和石油工业等领域，但电磁铁工作产生的焦耳热和电磁损耗会导致温度迅速升高、局部热应力和不均匀膨胀变形，严重影响稳定性和使用寿命。笔者采用有限元软件研究电磁铁温度、应力及变形的演化规律，分析导热套筒散热与强制对流散热对其热性能的影响规律。结果表明：随着线圈功率增大，电磁铁的最大温度、热应力和变形量均线性增大；随着套筒厚度增加，稳态的最大温度、变形量和导热量线性减小，温降幅度为12.5 ℃/mm；随着流速增加，最大温度、热应力和变形量显著减小，温降幅度45.5 ℃/(m·s^-1)，说明增强导热和对流均能提高电磁铁热性能且对流更为显著。

Numerical simulation of heat transfer characteristics and heat dissipation optimization for electromagnets

Electromagnets, serving as core hydraulic components in electro-hydraulic control systems, are widely applied in aerospace and petroleum industries. The operational generation of Joule heat and electromagnetic loss results in rapid temperature increase, local thermal stress and uneven expansion deformation, significantly affecting stability and service life. The evolution of temperature, stress and deformation in the electromagnet was studied using finite element software, and the influence of heat dissipation, with considering both heat conduction sleeve and forced convection, on its thermal performance was analyzed. The results show that the maximum temperature, thermal stress and deformation of the electromagnet exhibit a linear increase with the increase of the coil power. Additionally, the steady-state maximum temperature, deformation and thermal conductivity demonstrate a linear decrease with an increase in sleeve thickness, with the temperature drop recorded at 12.5 ℃/mm. Moreover, as the flow rate rises, there is a notable decrease in maximum temperature, thermal stress and deformation, within a temperature drop range of 45.5 ℃/(m·s^-1). This indicates that both enhanced heat conduction and convection contribute to improving the thermal performance of electromagnet, with convection exhibiting a more significant effect.